Portable jack



March 16 1926.

T. J. M CARTHY PORTABLE JACK Filed June 9, 1924 Patented Mar. 1 3:,1226.

UNITE STTES THOMAS J. MCCARTHY, 0F 110$ ANGELES, CALIFORNIA...

PORTABLE JACK.

Application filed June 9, 1924.

To all whom it may concern:

Be it known that I TnoMAs J. MolAR'rHY, a citizen of the United States,residing at Los Angelcs, in the county of Los Angeles and State ofCalifornia, have invented new and useful Improvements in Portable Jacks,of which the following is a specification.

This invention consists of the novel fea tures herein shown, describedand claimed.

The leading object is to make a jack having a supporting frame mountedon wheels and having a tongue for manipulating the location of thesupporting frame, the tongue also being adapted to serve as the jacklever.

Other objects and advantages will appear from the drawings andspecification.

The drawings illustrate the details of construction and operation of aportable jack embodying the principles of the invention.

Figure 1 is a top plan view of the portable jack as seen lookingdownwardly in Fig. 2, as indicated by the arrow 1.

Fig. 2 is a side elevation looking in the direction indicated by thearrow 2 in Fig. 1.

Fig. 3 is a sectional elevation on a plane parallel with Fig. 2 and onthe line 8-3 of Fig. 1, and looking in the direction indi cated by thearrows, and showing an operation.

Fig. 4 is a view analogous to Fig. 8 and showing a different operation.

Fig. 5 is an enlarged fragmentary detail of the jack dogs shown in Figs.3 and 4.

The details of construction and operation shown in the drawings are asfollows:

The main frame consists of tour arms 1 arranged radially and flat.Bearing blocks 2 extend upwardly from the arms 1 and the caster wheels 3have shanks mounted in the bearing blocks 2. A hearing block 4 extendsupwardly from the center of the "frame 1 and ribs 5 connect the bearingblock 4- to the bearing blocks 2. A housing 6 p is formed integral withthe arms 1 half way between two bearing blocks 2. A rectan gular orsquare opening 7 is formed vertically through the bearing block 4 andthe lifting member 8 is slidingly mounted in the opening 7 and hasratchet teeth 9 upon one side. The lifting member 8 is hollow and a flathead 10 has a hollow shank 11 fitting in the upper end of the hollow ofthe lifting member 8.

A secondarii lifting head 12 has a shank fitting-in t e hollow of theshank 11 and Serial No. 718,801.

a supporting flange 14L resting upon the head 10. The secondary head 12is adapted to be removed and the shank 13 inserted into the opening 15in the arms 1 out of the way when its use is not desired. The secondaryhead 12 serves to make the lifting member 8 higher or lower as desired.

The lever prongs 16 and 17 are formed integral with clamping members 18and 19 and the hand lever and ton ue member 20 is inserted between theclamping members 18 and 19 and bolts applied to secure the memberstogether. A supporting dog 21 is placed between the prongs 16 and 17 anda pivot bolt 22 is inserted through the prongs, through the housing andthrough the holding dog 21 so as to pivotally mount the handleconstruction and pivotally mount the dog 21 to support the liftingmember 8 when the upper end of the dog is in engagement with one of theratchet teeth 9. So far as the supporting operation is concerned,

it is immaterial whether the lever construc- 1 tion is up or down. Alifting dog 23 is mounted between the pron s 16 and 17 upon a pivot 24,the upper end or the dog 23 being adapted to engage a ratchet tooth 9and raise the lifting member 8 when the handle.

goes down. Slots are formed through the dogs 21 and 23 below their upperends and above the pivots, and a leaf spring 25 is mounted in the slotsupon pins inserted through the dogs, the tension of the spring beingexerted to press the uppcrends of the dogs away from each other.

Bifurcated ears 26 and 27 extend down wardly from the dogs 21 and 23respectively. A slotted link 28 is mounted the bifurcations oi the ears26 and 27 and pins 29 and 30 extend through the ears 26 and 27respectively and through theslots in the link 28. An expansive spring 31is inserted in the slot of the link 28 against the pin 29. A chain 32 isconnected to the link 28 and extends through the hollow of the handlemember 20 to the bell crank lever 33. A fitting 8% is clampedupon theswinging outer end of thelever member 20 and has a handle 35oflj'setlaterally from the axis of the handle member 20 and has a secondhandle 86 extending laterally. An eye, 37 is attached to a chain 38 andthe chain extends through the fitting 34 through the handle member 20and laterally through the housing 6 and is connected to a pin 39 tiredin the lower end of thelitting member 8 ,so that when desired the eye 37may be pulled to quickly raise the lifting member 8 into engagement withthe object to be lifted. The bell crank lever 33 is connected to thehandle member by a pin 40.

When it is desired to operate the jack to elevate the lifting member 8,the handle member is grasped in one hand and the bell crank levergrasped with the same hand to pull on the chain thereby pulling on thelower end of the dog 23 to bring the upper end of the dog intoengagement with the ratchet teeth 9, then as the handle is moved up anddown the lifting member 8 will be raised to the desired extent and thedog 21 will hold the lifting member in its elevated position.

The portable jack is intended especially for use around motor vehiclefor raising the axles to remove and replace tires, and so on, and thehandle construction, including the member 20, is of considerable lengthand serves as a tongue so that the lifting and supporting mechanism maybe readily run under the vehicle to a desired position. After thesupporting mechanism has been properly located a pull on the eye 37 willinstantly raise the lifting member 8 into engagement with the axle orother part to be raised and then one or more strokes of the hand levermechanism up and down will lift the part to the desired extent. If thepart is low, as when a tire is fiat, the secondary head may be removedand if the parts are of abnormal height the secondary head is used.After the operations have been per formed and it is desired to removethe jack, the bell crank lever 33 is released and the handles pressedclear down to the floor or ground and then the dog 23 will contact withthe dog 21 and press the dog 21 out of engagement with the teeth 9 andthe spring will hold the dog 21 out of engagement, and as the handle iselevated the lifting member 8 will go down considerable distance, and ifthis is not sud lent the operation may be repeated.

The operation of lowering the jack given in detail is substantially asfollows:

It is to be noted that the holding dog 21 has no up and down motion,being swivelled on the pivot bolt 22 on which the handle has a leveringoperation. The lift; ing dog 23 moves up and down. These dogs arepressed apart at their upper ends by the spring 25 and arepressedtogether at their upper ends by the action of-the spring 31. Thisaction, however, has lost motion on account of the pin 30 moving in aslot and functioning to thrust the lower ends of the dogs apart.

As above mentioned when it is desired to lower the jack the hand leveris pressed clear down to. the floor into a lower position than shown inFig.4, causing the dog 23 to disengage the dog 21 from the teeth. Thedog 21 will thereby be thrust out a considerable distance from the rack9. The handle is then raised and lowers the jack on the lifting dog 28.

In a certain position of the downward movement the )in 30 moves from theposition shown in t 1e slot in Fig. 5 to the other end of the slot andexerts a compressive stress on the spring 31. holding dog 21 intoengagement with the racl. The further upward movement of the handlelowers the lifting dog and the spring 31 exerting a stress to separatethe lower ends of the dogs and draws the upper ends the dogs together,thereby completely disengaging the lifting dog 23 from the rack, therack being held in this position by the holding dog 21. The handle isthen given an idle stroke downwardly which elerates the lifting doguntil the reaction of the spring 25 thrusts it into engagement with oneof the teeth. hen the weight is taken oft the holding dog 21 on to thelifting dog 23, the holding dog is forced outwardly as above describedand the upward movement of the handle gives a lowering action of thejack. This action may be repeated as many times as is necessary tocompletely lower the jack.

In the lowering operation it is unneccs sary to manipulate the bellcrank lever 33. However, it may be actuated if desired to positivelyforce the lifting dog 23 into engagement with the rack in any position.

Especial attention is called to the use of the handle parts 20, 35 and36 as a tongue for manipulating the lifting and supporting mechanism andas a lever for operating the ack.

When desired, the portable jack may be run under the center of eitherend of a motor vehicle and operated to lift the end of the vehicle,thereby placing the weight upon the casters of the jack, and then bymanipulating the tongue the end of the motor vehicle may be movedlaterally at right angles to the running line of'the vehicle, and byrepeating this operation both ends of the vehicle may be moved laterallyto any desired extent.

Various changes may be made without departing from the spirit of theinvention as claimed.

I claim:

1. A jack having a supporting frame, lifting member mounted thereon andhaving a rack, a lever pivoted on the frame, a pivottherefor, a holdingdog pivoted on the same pivot as the lever, a lifting dog pivotedbetween the said pivot and the rack. a tension device operating with thelever and connected to both dogs whereby both dogs engage the 'ack whenthe lever is operated to elevate the lifting member, and means to re-This forces the lease the tension device and disengage the.

holding dog from the rack to lower the lifting member.

2. A jack as claimed in claim 1 in which the tension device comprises aslotted plate, pins on said dogs engaging said slots, and means attachedto the lever to draw and release said plate.

3. A jack as claimed in claim 1 having a spring connecting said dogs toforce their teeth away from each other to disengage the holding dog fromthe hack.

1-. A jack as cla med in claim 1 in which the tension device comprises aslotted plate, pins on said dogs engaging said slots, means attached tothe lever to draw and release said plate, and a spring connecting saiddogs to force their teeth away from each other to disengage the holdingdog from the rack.

5. In a lifting jack, a supporting frame, a lifting member mountedtherein, a lever pivoted to said frame, a pivot therefor, a holding dogmounted on said pivot, a lifting dog pivoted on said lever, extensionson said dogs, pins thereon, a slotted plate engaging said pins, a springin one slot engaging the pin on the holding dog, a tension meansattached to the lever to operate the plate and thereby force both dogsinto engagement with the rack, and a spring between both dogs tensionedto normally separate the gripping teeth of the dogs.

In testimony whereof I have signed my name to this specification.

THOMAS J. MCCARTHY.

